Power electronics devices typically employ electronics packages that generally contain electrical circuitry for conducting electrical current which, in turn, generates thermal energy (i.e., heat). Automotive high-power electronics, such as those employed in electric and hybrid-electric vehicles, including power and control modules, injector drivers, DC-to-AC converters, and power steering electronics, typically generate a significant amount of thermal energy during operation. Excessive heat build-up may cause reduced performance including electrical circuit failure. Thus, thermal energy must be dissipated and transferred away from the electronics to ensure proper operation of the assembly. Additionally, the power capability of the electronics package and size of the electronics assembly generally depends upon the amount of heat dissipation that may be achieved.
Conventional electronics cooling approaches for dissipating thermal energy away from electronics include the use of a thermal conductive heat sink supported in contact with a surface of the electronics package(s). Power semiconductors in the form of flip chips and surface mount electronics packages having a top side cooling tab, e.g., inverted discrete packaging (DPAK) and thermally enhanced ball grid array (BGA), are typically cooled with a conventional finned heat sink. A fan circulates air across the heat sink fins for additional convective heat transfer to enhance the thermal energy exchange.
Another proposed approach to cooling electronics employs a thermal energy path coupled directly to the electronics assembly case through a pedestal. The pedestal contacts the power electronics package and conducts heat. The use of a heat conducting pedestal is beneficial when the assembly must be sealed to prevent moisture intrusion.
A further approach for cooling electronics devices employs a heat pipe device having a working fluid (e.g., water) disposed within a sealed pipe vessel (capsule). The conventional heat pipe device has a saddle interface that wraps around the circumference of the pipe and a heat exchanger opposite ends. When the saddle at one end is sufficiently heated by a heat source, e.g., power electronics device, the working fluid evaporates to transition from liquid to vapor and the vapor travels to the opposite second end of the vessel. Heat from an electronics device is thereby transferred to the working fluid which moves through the heat pipe to transfer thermal energy to the heat exchanger where thermal energy passes to the outside environment. Upon cooling, the vapor condenses back to liquid and returns to the first end via capillary action or gravity.
While prior known cooling approaches achieve significant cooling, it is desirable to provide for an enhanced electronics assembly and heat sink device that is capable of dissipating greater amounts of thermal energy (heat) away from the electronics package in a cost affordable and optimal manner. It is particularly desirable to provide for cost affordable and enhanced cooling of automotive electronics to cool high-power electronics packages that may be employed on an automotive vehicle.